Forbidden
by Karevsanatomy
Summary: A case of mistaken identity has Meredith and Mark crossing lines neither of them thought possible. Adult content


-1_There is nothing better than dirty, hot, sweaty sex. I was in the mood, for lack of a better word, to write a dirty little something or other. If you are not into Meredith and Mark, I suggest you stop reading right here. Of course, if you are just into anything hot and sexy I say go for it, despite your pairing preference! _

It to be the hottest day in August. The sort of day when the air is thick with humidity and sweat drenches a body with the slightest movement. Naturally it had to be the day Derek's air conditioner gave out. Any other time Mark would have said fuck it and retreated to his blessedly cool hotel room, but Derek had made him promise to wait for the new unit to be delivered.

After hours of sitting on the deck, wearing little more than a pair of cut off shorts, Mark decided it was time to cool off. The lake was out of the question, as he did not swim in any body of water that he could not see pr touch the bottom of. That left the shower, if a person could call the tiny stall a shower. It had all the right parts, a head that spouted water, a drain to let out the excess, and a frosted glass door to prevent the floor outside from getting soaked.

Mark unsnapped the fray bottomed shorts and let them fall to the floor. He wasn't a fan of underwear, so there was nothing stopping him from entering the shower once his only piece of clothing was discarded. Cool water caressed his blazing skin the moment he stood under the spouting head. The spray wasn't as hard as the one back in his hotel room, but then this shower wasn't as fancy either. 'Damn Derek and his shitty ass promises,' he thought sourly. He wanted to leave, to just forget he had ever made the promise; it was what he would have done in the past. He had turned a new leave though, and that meant no breaking promises; even if he sweated to death.

He closed his eyes, letting the water course over his body, while he leaned back against the cool metal of the shower wall. Thank God for stainless steel showers, he thought with amusement. For lack of something to do, his fingers found his cock and wrapped around the semi-placid flesh. It didn't take much for the softness to turn hard as he methodically stroked his hand from the base of the shaft, up the ten and a half inches to the head. To make his job easier, he reached for the bottle of shampoo, squirting a small amount in the palm of his hand; he then returned to stroking himself, this time each caress eased by the lubricant of the sudsing shampoo. He started to groan with a small amount of satisfaction when he heard the trailer door open and then slam shut.

"My God it's like an oven in here," Meredith cried from the other side of the frosted glass door. "Seriously, how are you standing this?"

Mark cleared his throat, ready to apprise her of his identity when he heard the rustling of clothing. His softening cock sprung back to attention, his fingers tightening around the inch and half thickness. Using his free hand, he cleared some of the steam from the glass. He was only able to make out the outline of Meredith's body as she lifted her top up and over her head. The bright colored fabric disappeared in the general direction of the bed. His hand worked up and down as he watched her shimmy out of her shorts, leaving her clad in what looked to be a white bra and matching thong.

"What are you doing?" She gasped, facing the shower. Mark looked down, at his hand wrapped around his cock. She had caught him, she had seen him jacking off in the shower. "Seriously, Derek, are you that hard up?"

Mark realized that now was the perfect time to correct her. He told himself he was going to, that he wasn't going to let her think he was Derek. Her next words stopped him, though. "I guess if you're going to put on a show, I might as well give you some…inspiration."

He heard the scrapping of a chair across the linoleum floor that was just outside the shower. Before long a kitchen chair is positioned three feet from the door, giving him a better view of Meredith's outline. "Can you see me?" She asked. All he could do was nod. Oh yeah, he could see her. "Good. You watching?" Again, all he could do was nod.

His silvery blue eyes were transfixed on her as she twisted her arms behind her back to unhook her bra. Blood gushed to his cock when her small breasts were free from the lacey restrains. She ran her hands over the mounds, her fingers circling the pale pink nipples, tweaking them into hard little pebbles. God damn, he thought, Derek is one lucky son of a bitch.

"Aw, you stopped. Need some more inspiration do you?" Meredith purred. Mark gulped, wishing the glass wasn't frosted when she slid the thong down her slender legs. She sat on the edge of the chair, leaning back slightly and spreading her legs. "I want you to think about me while you're stroking your cock. I want you to pretend it's me. I know I'm going to think about you. I'm going to imagine that it's your fingers fucking me." The dirty words should have sounded crude, they should have been a turn off, but they weren't. Not for Mark. He liked nothing better than to see a pretty little mouth whisper words so dirty they would make a sailor blush.

"Come on, baby, think of me. Think of my hand running up and down your cock." Meredith whispered above the din of the shower. His mouth dried out when she parted her pussy lips with her thumb and forefinger. If not for the opaque glass he would have had a perfect view of her pussy. She slid her middle finger into the pink flesh as far as it would go, making a small mewing sound of pleasure. "Oh, God, that feels so good," she moaned, stroking her slender finger in and out at a rapid pace. She reached down with her other hand and used her thumb to toy with her swollen clit.

It was killing him, watching her pleasure herself. No amount of stroking seemed to relieve the pressure that was building, giving him an almost painful erection. His breath came in raspy pants as he tried to relieve himself. He closed his eyes, stroking harder, faster. He didn't notice when she stopped fingering herself, and had no clue to her intentions until he heard the shower door starting to creak open.

"Oh. My. God." Meredith shrieked, her pale cheeks blazing with heat. "Ohmygod. Ohmygod. Ohmygod." She looked ready to faint, as though someone had yanked the floor out from under her. "Oh. My. God."

"I've been told I'm a God," Mark quipped weakly, in an attempt to lighten the situation. His gaze dropped to her body. The unobscured view was even better than he had imagine. Her breasts were the perfect handful, with small, pouting, pink nipples. He could almost count her ribs, she was so slender, and her stomach concaved quite nicely in the way that models usually did. His fascination was centered on what was between her legs though. She was shaved clean, not a bit of hair hiding her pussy from view. "You've got exactly five seconds to run before I grab you and fuck your brains out."

Mark knew she would run. She was Meredith, and she belonged to Derek. She surprised him though, and stood there, her wide green eyes staring at him in a confused manner. Silently, he counted to five, and then reached for her. He slammed her against the wall, thankful for the small space. "One last chance to say no, Mer."

She lifted her arms, her hands grasping his neck. She tugged his head down and kissed him, her tongue sliding between his lips. Her sparred with her, their tongues mating in an age old manner. Anxiously, he slid his hands down her body, needing to touch the soft, pink flesh between her legs. He knew it would be wet, and not with water. He wasn't disappointed. She had done the work for him, working herself to almost a climatic state and leaving herself ready for his aching cock.

He grabbed a hold of the back of her slender thighs and lifted her until their bodies were perfectly aligned. She tried to wrap her legs around his waist. Using brute strength, he spread her legs wider, bumping one knee against the door and the other against the wall. The head of his dick rubbed against her pussy lips, lubricating himself before he eased into her tightness. He inched in slowly, letting her accustom herself to his size.

"Now," Meredith whimpered. "I want it all…now." He gritted his teeth, and then shoved himself in up to the hilt. Her vaginal walls clenched him, milking him as he thrust in and out, hitting her cervix each time. "Ohmygod. Ohmygod. Ohmygod. Yes. Right there. God. Yes." Her nails dug into his neck, raking down his back. He winced as skin was scraped away. "Fuck me, Mark. Fuck me. Harder."

The dirty little words from her sweet lips spurred him on. He pumped in and out of her, needing to find release. He found it sooner than he hoped, and was barely able to pull his softening cock from her warm body before hot, white cum trickled from the head of his dick.

"Oh. My. God." Meredith breathed, swaying slightly when he let her legs fall to the shower floor. "I…oh my God." She stumbled out, her body shaking as she gathered her clothing. "We have to hurry. Derek…Derek wanted me to meet him out here," she whispered.

"Meredith," Mark started, loving the way her name now felt on his tongue. She looked over her shoulder at him, horror and tears blurring her green eyes. The guilt stamped on her features crept over to him. They had betrayed Derek in the worst way possible. They had done the very thing that had been forbidden…

_TO BE CONTINUED….._


End file.
